[dyed_in_the_wool]

This may be the dumbest article I've ever read.
I feel stupider for having glanced at it.

[dyed_in_the_wool]

The crux of her argument is based on percentage of income taxed. However, what she fails to mention is that in terms of income replacement, she and Eisner (her example) get a significant percentage less. So even if he's paying in @ .5% for Social Security, his income replacement is still going to be capped at whatever SS max is (@ $13K I think).
SS is a sop to anyone the closer they get to the Covered Comp limit. Any benefit person worth their salt knows that.
If she thinks the percentage is too high or is trying to suggest a 'graduated' rate, well no way.
Outside of the covered comp limit, the flat tax would work the same way.